Two options for this:

1. Find a way to pass through HDMI audio (ideal, but maybe some hardware limitations?)
2. Support a 3rd party device like the JetKVM Audio Expansion by @calvss

I noticed there was an older issue asking about sound, but it wasn't framed as a feature request, but rather as a bug. The latency on the JetKVM is low enough that sound support seems feasible and remote viewing/listening over IP would work okay.

I personally have a use case for this: remote SDR, with the audio being demodulated on a Raspberry Pi, instead of trying to pass the SDR through the network (which requires better latency, thus more dropouts in many cases).

But others have expressed interest in watching movies/YouTube, and even light gaming (not too latency-sensitive) through the KVM...